optical depth of detection

Background and Objectives: Nanoparticles of titanium dioxide are now widely used both for the creation of sunscreen filters, and as carriers of drugs. One of the ways of transepidermal delivery of these nanoparticles to the dermis of the skin is their penetration into the hair follicles. However, optical control of the filling of follicles with nanoparticles is rather difficult due to strong light scattering in the skin.